Electro-optic devices containing liquid crystal materials have become commercially important recently because of their low power requirements and good contrast, particularly for applications such as watch faces, calculator displays and the like. Although liquid crystal compounds have been known for many years, the discovery of nematic liquid crystals that have a transition temperature range that spans room temperature sparked a renewed interest in these materials and greatly expanded their marketability. Research is continuing to discover new room temperature liquid crystal materials and mixtures and for liquid crystal materials having improved contrast in electro-optic devices.